condition mean min max ZT0-3 18.3869 18.3869 18.3869 ZT4-7 12.302299999999999 12.302299999999999 12.302299999999999 ZT8-11 11.2708 11.2708 11.2708 ZT12-15 13.161349999999999 13.161349999999999 13.161349999999999 ZT16-19 20.2837 20.2837 20.2837 ZT20-23 18.5689 18.5689 18.5689